The present invention relates generally to electrical connector assemblies and more particularly to a modular, solderless connector assembly and method for connecting data terminals and peripheral equipment to a central computer. The installation system of the invention allows persons of little computer experience to add, remove or interchange terminals and peripheral devices in the system without disturbing data cables or the connections at the computer input/output ports.
In many offices, business, research and manufacturing applications, it is customary to connect peripheral devices to a central computer through some form of cable network. Such peripheral devices may include data terminals, printers, plotters, modems, bulk data storage devices, optical readers, vision systems and the like. To accommodate a plurality of peripheral devices, many computers are provided with a bank of input/output terminals or ports. Each port is connected to a data channel or group of channels, through which the computer central processing unit (CPU) communicates with the outside world. Many input/output ports are configured as serial ports, although parallel ports are also prevalent.
In permanent and semipermanent installations, the central computer is usually installed in a fixed location, preferably a centralized location, where a favorable physical environment can be maintained. The peripheral devices, on the other hand, are usually located at work stations or points of convenience, often quite remote from the computer itself. Connecting cables, run through duct work in the walls, floor or ceiling or run along baseboards, are used to connect the computer with the peripheral devices. In many instances, these connecting cables may conform to the RS-232 interface standard established by the Electronic Industries Association (EIA). The RS-232 interface uses a standardized 25 pin connector, known in the trade as a DB 25 connector. The DB 25 connector provides two rows of in-line pins which carry pre-established signals according to the standard. Although 25 pins (25 signal paths) are defined by the standard, often fewer than 25 pins are often needed to connect the peripheral device with the computer. For most peripheral devices, 6 pins are usually more than enough.
Where computer systems are involved, change can be counted on. New peripheral devices may be added and old ones may be replaced or relocated, depending on the changing needs of the workers. Also, since peripheral devices are expensive, it is often desirable to share a peripheral among several users. Preferably, this would be done without having to unplug and physically relocate the device, as any unnecessary movement increases the likelihood of damage. As a practical matter, most computers have only a finite number of physical input/output ports to which peripheral devices may be attached. When the number of peripheral devices in the system exceeds the number of input/output ports, some arrangement must be made for switching several devices between a single port. Although port sharing devices are commercially available, most do not provide the desired flexiblity. Many prior art port sharing devices are limited in the number of peripheral devices they will support and cannot be readily expanded.
The present invention overcomes the deficiencies of present day port sharing devices and connectors by providing an installation board which may be configured in a multitude of ways and which provides modular subcomponents to allow for expansion.
The invention provides an installation system comprising one or more modular circuit boards, each having a first plurality of traces and a second plurality of traces. A first jack is electrically coupled to the first plurality of traces and a second jack is electrically coupled to the second plurality of traces. Both jacks are secured to the circuit board, preferably along one edge thereof. The invention further comprises a first connector secured to the circuit board and electrically coupled to the first plurality of traces for coupling to a first entrance cable. A second connector is secured to the circuit board and electrically coupled to the second plurality of traces for coupling to a second entrance cable. The entrance cables may be provided with DB 25 connectors or the like in order to interface with existing computer equipment, peripherals and existing connecting cables. The invention further provides at least one jumper cable having plug connectors at the ends thereof for removably engaging the first and second jacks in order to establish electrical communication between the first and second connectors.
The modular circuit boards are arranged in a space saving stacked fashion within a protective housing. The housing has a front face with a plurality of apertures which register with the jacks associated with each circuit board. Preferably, the jacks are modular jacks, such as RJ-11-style modular jacks or telephone jacks, providing up to six conductors each. The plugs at the ends of each jumper cable are also modular plugs, such as RJ-11-style plugs or the like. The jumper cables may be straight cables or they may be retractable coiled cables.
The individual modular circuit boards are secured to the underside of the front panel, the boards standing off at right angles to the panel and being generally parallel to one another. Each board is removably secured to the panel using a bracket which includes a planar metal panel or plate in spaced parallel relation to the circuit board. The plate helps shield the boards from one another and from electromagnetic interference. The connectors each lie on a line which forms an acute angle with the edge of the circuit board along which the jacks are disposed. The connectors are each disposed a different predetermined average distance from the edge along which the jacks are secured. This arrangement allows a plurality of entrance cables, laid parallel and side-by-side, to fit within the space defined by adjacent circuit board modules and the protective enclosure.
The resulting package is neat and compact, for installation in practically any location. Using the invention, interfacing a computer with peripheral devices (or other computers) is simply a matter of plugging a jumper cable between the appropriate jacks. The jacks may be labeled on the front panel when first installed by a technician. At that time, the correct RS 232 wires are selected from each entrance cable and secured to the circuit board connectors. Once this is done, connecting a peripheral device to a computer input/output port is quickly and conveniently accomplished by even those without computer experience.
The invention also saves time and money in interfacing a computer with remotely located peripheral devices. According to the inventive method, a first group of data cables is installed from a central location in the vicinity of the computer to a plurality of remote locations where it is intended to operate a peripheral device. The data cables can be prewired from the peripheral locations or from receptacles located throughout a building to a single point in the computer room. Any tradesman can do this, keeping installation costs to a minimum. According to the method, a second group of data cables is fabricated, each of the second group being approximately the same length and having a connector at one end adapted to be directly connected to a computer port. Preferably, the number of cables in this second group is equal to the number of computer ports. The second group of cables forms an umbilical cord which is slightly greater in length than the distance between the computer and the central location where the installation system board is to be installed. The connector on each cable in the second group of cables is then connected to a computer port with the opposite ends of the cables being positioned at the central location where the installation system board is to be installed. The installation system board or panel is then installed at the central location. The unconnected ends of each cable in the second group is then connected to a selected one of the plurality of jacks on the installation system board or panel. Further, according to the method, a jumper calbe having a plug at each end is installed between a first jack connected to a specific computer port and a second jack connected to a cable in the first group of cables which extends to the desired remote location. This jumper installing step is then repeated for each of the computer ports to be used.
For a more complete understanding of the invention, its objects and advantages, reference may be had to the following specification and to the accompanying drawings.